Telephone-switchboard apparatus.



No. 663,5". 7 Patented Dec. ll, I900. W. S. PACA.

TELEPHONE SWITCHBOARD APPARATUS- (Application filed Feb. 16, 1900') (No Model.)

m5 uonms PETERS co, Pnu'muwm WASHINGTON. u. c,

WILLIAM S. PAOA, OF ERIE, PENNSYLVANIA, ASSIGNOR OF ONE-HALF TO PETER H. ADAMS, OF SAME PLACE.

TELEPHONE SWITCHBOARD APPARATUS.

SPECIFICATION forming part of Letters Patent No. 663.511, dated December 1 1900.

Application filed February 16, 1900. Serial No. 5,463- (No model.)

To all whmn it may concern:

Be it known that LWVILLIAM S. PAOA, a citizen of the United States, residing at Erie, in the county of Erie and State of Pennsylvania,

5 have inventedcertain new and useful Improvements in Telephone-Switchboard Mechanism; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled E0 in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to the letters and figures of reference marked thereon, forming part of this specification.

My invention relates to improvements in multiple-switchboard mechanism, and is designed to facilitate the testing of the lines by the operators to find out whether a subscribers line called for is in use. A multiple switchboard is ordinarily composed of a plurality of boards or sections, to each of which the lines of all of the subscribers are branched or connected, so that the operator at any board or section can connect up any two lines desired; but if one of the lines desired has been already connected up at another board or section the plugging in of another operator on one of the lines so connected up creates an interruption or disturbance of the lines so in use. Heretofore many types of mechanism have been devised for the purpose of testing the lines to find out whether they are in use before plugging in upon them, some of which mechanisms are in common use, an example of which is the so-called click-signal, the operation of which is well understood.

In my invention I have done away with many of the difficulties common to the busytest systems now in use and simplified the construction of the mechanism, by means of which my busy test can be operated so that the operator at any board or section can at once determine whether any line desired is in use without in any degree interfering with or interrupting such use. I accomplish this result by connecting the frames of the jacks forming the terminals of each line on all of the boards or sections to one side of a localbattery circuit having resistance-coils therein and make the switch-plugs with a coil connected to the other side of said local-battery circuit and also to the point of the switchplug, so that when a plug is inserted in any one jack of a series the circuit is closed, so that by touching the point of another switchplug to any other jack of said series so plugged in upon a circuit is completed through the coil in the plug to the point thereof and thence through the jack-frame touched, so that the point of the plug becomes magnetized and adheres to the frame of the jack so touched, thereby indicating that the linewith which said jack is connected is in use. These and other features of my invention are hereinafter set forth and explained, and illustrated in the accompanying drawings, in which Figure l is a diagrammatic View of a portion of a multiple switchboard embodying my invention. Fig. 2 is a sectional view of a jack and switch-plug forming part of my invention.

In Fig. 1 the numerals 1 and 2 designate two subscribers telephone apparatus, and the numerals 1 and 2' designate portions of the operators apparatus at two sections of a multiple switchboard, and the drawing further illustrates telephones Nos. 1 and 2 connected up and in use, while the operator at station 2 is testing to find out whether the line leading to telephone No. 2 is in use. Referring further to the drawings, at station 1 I show an operators switch and telephone A, ring-off drop A, and magneto A which are of the usual construction, as are the connections ff to the switch-plug F and the connections F and f to the switch-plug F, and at station 2 a portion of the same mechanism is shown, together with a switch-plug F and its connections at station 2. These features are, however, of the usual and ordinary construction and operation.

The line a from telephone No. 1 extends to line a, which by branches a connect with the insulated collars I) (see Fig. 2) of the series of jacks B,Which collars are adapted to receive and contact with the stems of switch-plugs F, inserted therein. The line C from telephone No. 1 extends to and is connected by the line through a drop-magnet D and by a branch d with the armature e of an ordinary relay E in the usual manner, and thence by line 0 to line 0 and from thence by branch lines 0 to the tongues b of the series of jacks B, so that when the stern of the switchplug F is inserted in the collar 1) of one of the series of jacks B it operates to connect the line f, leading from station 1 through the collar b, with the line a and thence through the lines a and a to telephone No. 1, and through line f and tongue I to the lines 0 and their connecting lines directly to telephone No. 1.

From telephone No. 2 the line h extends to a line h and thence by branch lines h to the insulated collars b in the series of jacks B", which collars are adapted to receive and contact with the stems of switch-plugs F, in.- serted therein, and the line H from telephone No. 2, extends to and connects by the line H through a drop-magnet D and by a branch d with the armature e of an ordinary relay E in the usual manner, and thence by the line H to the line H and thence by branch lines H to the tongues b of the series of jacks B, so that when the stem of the switch-plug F is inserted in the collar 12 of one of the series of jacks B it operates to connect the switchplug line f leading from station 1 through the collar 1), with the line if, and thence through lines h and h to telephone No. 2, and by switch-plug linef through thejack-tongue c, and through the line H and their connecting lines directly with telephone No. 2. These features are of the usual construction and arrangement in use in multiple switchboards and are shown in connection with the novel switch-plug and local-battery circuit, hereinafter described.

The local-battery circuit comprises a local battery G with lines g and g leading therefrom, the line 9 extending to and connecting by means of a branch line g with the lines f f and f of the switch-plugs F F F as and for the purpose hereinafter set forth, and also through resistance-coils G and lines g and branch lines 9 with the frames of the series of jacks B and B, the resistance-coils G operating to sufficiently resist the travel of the current toward the line 9 on its return to battery G to cause it to traverse the branch lines g and the frames of the series of jacks B B" before it passes the resistance-coils G on its way back to the battery G. To the jack-tongues b are connected branch lines 9 which join lines I, leading to and connected with lines I and I, which lead to the relays E and E, while the line g from the battery G connects with the relay E and by a branch 9 with the relay E, so that when the switchplugs F and F are inserted in the jacks B or B a circuit is formed from the battery G through the contact of the jack-tongues b with the lugs Z7 on the jack-frame through the wires I and g and wires I or I through the relay E or E to the wire 9, and back to the battery G.

The switch-plugs F, &c., are constructed (see Fig. 2) with a point of magnetic metal L, which is insulated from the remainder of the plug by insulation 1, and adjacent to the insulation Zis a coil L, one end of which, 1, connects with the point L and the other with the stem M of the plug-say at m. This stem connects with wire f leading to the local battery line g and is insulated from the hearing M, which connects with the line f, leading to the operators switch mechanism 1, and is adapted to contact with the jack-touguel), surrounding the stem M of the bearing M, and insulated therefrom by insulation n is a shell N, adapted to contact with the insulated collar 1) in the jack B, and leading therefrom is a line f, connecting with the operators switch mechanism. Ilhrough the linefflconnecting withlthe line g of the local-battery circuit, when the pointL ofa plug isbrought into contact with the end of one of the jacks B, as illustrated by plug F connected with operators set No. 2, if a switch-plug, as F, is inserted iuone of the series of B, a connection isiinade between the point L of the plug andthe jack-frame connected with; the opposite side of the local circuit, which excites the coil L, so as to magnetize the point Let the plug, which causes it to.adhere to the jack so touched, showing that the subscribers line connected with such jack. is in use; but if the plug E is not inserted in the jack,,as shown, thennocircuit will be set up, and as the point of the plug is not then magnetized it does not adhere to the jacktouched thereby, which indicates tothe operator that theline is not in use;

The jack B or B" is constructedof soft iron or other magnetic metaland is provided with an. opening for. the insulation of the switchplug, which is lined with a. metal collar. 12, which is insulated from the remainder of the jack andconnected with the lines a or 71?, as the case may be, while to the rear endof the jack are secured contacttongues b and b insulated from each. other. and from the jackframe, and on the jack-frame there is a contact-pointb adapted. to connect the tongue 19 when the switch-plugis in place, as clearly shown in Fig. 2. The operation of. these parts, together with the partsof the switchplug, in connection, with the telephonic and local circuits has been heretofore clearly explained, so that further description thereof is deemed unnecessary.

I have thus shownanddescribed a convenient mechanism and arrangement of circuits for utilizing my invention; but I do not desire, to confine myself to the exact construction andarrangement herein shown and de-' scribed, as I am aware that both the mechanism and its arrangement may be considerably modified without departing from the spirit of my invention. Therefore What I. claim as new, and desire to secure by Letters Patent. of the United States, is 1. In a multiple switchboard, the combination of two or more duplicate sections, jacks forming terminals for each subscribers line on each of said sections connected up in open circuit with a local battery, switch-plugs adapted, when inserted in any jack of a series,to connect a subscribers circuit, and also connect with one side of the local circuit all the jacks of the series so plugged upon, and a coil in the switch-plug connected with one side of the local-battery circuit and adapted to complete such local circuit through any jack of the series plugged in upon, by bringing the tip of such plug into contact therewith, whereby the point of such plug becomes magnetized, substantially as and for the purpose set forth.

2. A switch-plug for telephone-switchboards,comprised, substantially, of acoil connected at one end with a local-battery circuit and at the other with an insulated tip of magnetic metal and adapted, when said tip is brought into contact with the other side of said local-battery circuit, to become magnetized, substantially as and for the purpose set forth.

3. The combination of a jack for telephoneswitchboards connected with one side of a local-battery circuit, a switch-plug having a coil connected with the other side of said localbattery circuit and a tip of magnetic metal on said plug connected with said coil and adapted, when any one jack of a series is plugged in upon, to be brought into contact with any other jack of the series so plugged in upon and complete the circuit through said jack-frame with the local battery, whereby the tip of the plug becomes magnetized and adheres to the jack so touched, substantially as and for the purpose set forth.

' In testimony whereof I afiix my signature in presence of two Witnesses.

WILLIAM S. PAOA,

Witnesses:

FRED EINFELDT, H. J. OURTZE. 

